So as to get off the topic of mergers and all that I thought it would make a nice change if I started a thread which as stated is about your most memorable flight(s). Simple really, although I want it to be for all the right reason, I dont really want any negative flights, just ones that stood out for you. I would try and limit it to two otherwise it gets too much.
Here's my two cents.

18th January 1999 when I flew Concorde from JFK to LHR on my Birthday, the whole experience was fantastic from check in to the landing.
The take off is clearly the best part of the journey for me, the noise of the Olympus engines, screaming down the runway and the pure acceleration was a joy in itself. The onboard service was second to none, all passengers went up to the flight deck during the flight (light load) and had a chat with the crew. Shania Twain was onboard as well. A very memorable time.

My second flight, is the first time I flew First Class on UA, over 10 years ago, again JFK to LHR, on a 767. I was pampered to heaven and back and of course in those days we had caviar and Dom!

Got to be in April 2000. I was working as a student language teacher for Air France, in Paris at CDG). I booked a ticket home for the weekend, and thought I might as well fly Air France for once (didn't have any non-rev rights ). I mentioned to my manager, though, what I was doing.
I checked in, and boarded the flight. After a few minutes, the purser came over and said, "Excuse me, Mr. x, would you like to come this way?" I thought, excellent, my manager knew her and I've been upgraded! We walk through the business class section of the A320... and into the cockpit! I was asked if I wanted to sit on the jump seat for the flight! Of course I did!
Saw everything, chatted to the pilot (I remember his name to this day!) and had a fantastic flight. Amazing to see, the aircraft practically flew itself. And the view out of the front on approach to LHR was amazing too.
A pity that jump seat travel is now to all intents and purposes impossible

Flying aboard a NatureAir DH6 from Quepos to San Jose. It was my first time on the DH6. The entire experience was brilliant, from the tiny airfield that was like no other I have visited and the two-foot-long DH6 windows and no cockpit door to the amazing Costa Rican scenery not far below. That experience made me desperate to fly other small turboprops, so I've now got flights booked on the D28, BNT, J31, SF3 and BNI. I'll hopefully also book flights on the SWM and L4T.

"Everyone writing for the Telegraph knows that the way to grab eyeballs is with Ryanair and/or sex."

My most memorable flight was my first time with BA (ARN-LHR-LAX). I got for the first time to fly via LHR, and it wasnt so bad as many say. And the whole flight was brilliant, and had never met such a nice cabin crew. The whole experience was just brilliant.

Being one the only flights on 12/13/07 to land in Boston while they where having a nearly white-out blizzard. I'm not sure how we were ever allowed to depart ATL. It was interesting because you could tell that the pilot was nervous, and he had reason to be!. When we landed I could not even see the asphalt on the runway! The adrenaline was really rushing then.

The most memoriable flight for the was the last TWA Transatlantic Flight TW721 LGW-STL in Trans World One Class (Business Class) 1 C, N691LF.

As I am a huge TWA fan I bought a full fare ticket for this route. I know it sounds silly but I had the time of my life!
We got water canon salutes in both Gatwick and St. Louis. It was the last flight for the Captain as he retired that day! All crews oboard were very lovely (like TWA was! ) and after landing everybody on board had tears in the eyes!

As might be for others -- my very first flight. Nine years old. TWA Super Connie. MCI - PHL to visit family. I think I had already left the ground before we took off -- I was so excited. My heart was in my throat as those engines went full throttle and we rolled. A mix of excitement and terror! Will never forget it. Got wings and some kind of other kiddie packet also from the "hostess".

I was 7 years old back then, and it was quite an exciting experience. The 744 suffered some technical problems in FRA, the flight was cancelled and all pax were rebooked on the flight the next day.
My parents had flown to HRE one day earlier (they had free tickets for an Affretair DC-8 Freighter, but no kids were allowed), so I had to spend the night in the Sheraton airport hotel.
I felt really worried at first (being on my own), but the LH F/As took good care of me, with one of them staying in the room next to me all the time.
Finally, I arrived one day late (my parents felt really relieved, as they worried more than I did ).

I'm sure this flight triggered my interest in aviation.

Today, 13 years later, I hope to get aboard this particular 744 some time (it has to be D-ABTC, my aunt still has a photo of it on the tarmac in HRE).

One of my memorable flights was back 2 (almost 3) years ago when I went on a class trip to the east coast on UA. We had to be at LAX by 4am so I remember being quite dazed but extremely excited to be going away from home with lots of friends for 2 weeks. One funny thing as we were checking in, the social studies teacher (the group leader) checked in first and I was right behind her. As she steps up to the counter in T5 and puts her bag on the scale, the lady behind the counter says the bag was 25 pounds over the limit, so I and the other 56 people in the group start to laugh with the teacher. The flight to IAD went by very quickly as everyone was really energized. The return flight back from BOS was equally as fun. That was an experience I'll never forget.

Another of my memorable flights was flying on B6 last summer for a trip to Ft. Lauderdale, Florida. Everything from the flight crew to the plane itself to the IFE, everything about that flight was great.

It was a lifelong dream to fly on the Concorde, so when they announced that the Concorde would stop flying, I immediately booked in on QF/BA SYD-JFK-LHR-BKK-SYD for no other reason than to fly on BA02. Did the whole thing end-to-end in a couple of days using the money I was saving up for a motorbike. Worth every penny.

On 10-May-2003, I flew BA2 (G-BOAE) from JFK to LHR in 3h17m.

"Those of us who have lived in the age of the extraordinary Anglo-French flying machine will be able to tell our grandchildren: your new toys are well and good, but we had Concorde." Financial Times - 16/8/2000

The most memorable flight for me was this one on the Inaugural A380 flight from SYD-SIN.

and probably my last flight back in February on a Qantas 747, nothing special about it but it was my last flight I have taken so it kind of sticks in your mind the most until I get a chance to take another flight.

It would have to be my first time on a 747, back in 2004, a United flight from SFO to DEN. I was nonreving on it and it looked like it was going to be full; however, at the last minute, they cleared me and gave me a seat in the first C cabin on the main deck. I felt like a kid in a candy store. Sure, I had been on planes which had more bells and whistles than that one, but the fact that it was a 747 made it a really special day for me. Amazing machine.